Method: UIImage#rotate

Defined in:

lib/sugarcube-image/uiimage.rb

#rotate(angle_or_direction) ⇒ Object

# File 'lib/sugarcube-image/uiimage.rb', line 361

def rotate(angle_or_direction)
  case angle_or_direction
  when :left
    radian = -90.degrees
  when :right
    radian = 90.degrees
  when :flip
    radian = 180.degrees
  when Numeric
    radian = angle_or_direction
  else
    raise "Unknown angle/direction #{angle_or_direction.inspect}"
  end

  w = (self.size.width * Math.cos(radian)).abs + (self.size.height * Math.sin(radian)).abs
  h = (self.size.height * Math.cos(radian)).abs + (self.size.width * Math.sin(radian)).abs
  new_size = CGSize.new(w, h)
  new_size = self.size

  # Create the bitmap context
  UIGraphicsBeginImageContextWithOptions(new_size, false, self.scale)
  bitmap = UIGraphicsGetCurrentContext()

  # Move the origin to the middle of the image so we will rotate and scale around the center.
  CGContextTranslateCTM(bitmap, new_size.width / 2, new_size.height / 2)

  # Rotate the image context
  CGContextRotateCTM(bitmap, radian)

  # otherwise it'll be upside down:
  CGContextScaleCTM(bitmap, 1.0, -1.0)
  # Now, draw the rotated/scaled image into the context
  CGContextDrawImage(bitmap, CGRectMake(-new_size.width / 2, -new_size.height / 2, new_size.width, new_size.height), self.CGImage)

  new_image = UIGraphicsGetImageFromCurrentImageContext()
  UIGraphicsEndImageContext()
  return new_image
end